Baltimore police did not have permission to conduct training exercises at the shuttered state facility for the developmentally disabled where an officer was shot and critically wounded, according to Maryland health officials.

"As far as we can tell, there were not requests made by the city Police Department to use the facility for training," said Dori Henry, a spokeswoman for the Maryland Department of Health and Mental Hygiene. "We're looking into how they came to be there."

Police have not disclosed details of their internal investigation into the incident at the former Rosewood Center in Owings Mills, but Anthony Guglielmi, chief spokesman for the Baltimore department, acknowledged that police have known that the use of the building was unauthorized.

The revelation comes on top of several other problems identified by the department in the accidental shooting of a University of Maryland campus officer training with Baltimore police.

Senior officers were not aware of the exercise, and an instructor's service weapon was somehow confused with a paint-cartridge gun used for training. Sources have told The Baltimore Sun that investigators are examining the possibility that the accidental shot was not fired as part of a drill.

As part of the Baltimore department's review of training, Guglielmi said, police officials are trying to determine whetherother sites have been used without approval. For years, police have used a city garage on West Dickman Street in South Baltimore, and the training academy is supposed to manage the use of other sites.

Training experts say the use of abandoned buildings is common, but police should have safety procedures in place and get owners' approval.

Documents show that when Baltimore County police sought to use the facility for training, the department had to give advance notice and agree to detailed terms. The Rosewood Center closed in 2009.

In a letter that year, the Maryland Department of Health and Mental Hygiene told Officer James Bossi of Baltimore County's tactical unit that officers could conduct training sessions, including "day and night building searches and room clearing exercises without live weapons." The department said training sessions could be conducted only on weekdays and that county police had to give at least one day's notice.

The Maryland Department of Health and Mental Hygiene said it had no liability in the event of an accident or injury, and that county police would be responsible for repairing any damage.

"As long as these conditions are met and followed, DHMH will grant access to BCTU until the sale of the Rosewood Hospital Center," the letter says.

But three years later, there were added requirements. In an email dated Oct. 1, 2012, a state official wrote to a county police bomb squad commander about a recently completed training event with the Department of the Army.

"It proved to be difficult to coordinate but ultimately we were able to make some rare accommodations," wrote Jerimiah Sabir, deputy director of the Department of Health and Mental Hygiene's capital planning office.

"For future events to go smoothly," Sabir wrote, the state needed 90 days' notice in order to create a "right of entry" agreement. Cpl. Robert Conroy replied that the county bomb squad probably would not use the facility anymore because it could not meet the 90-day requirement.

"Our unit training evolutions are often arranged at the 'last minute' based upon our schedules and work demands," Conroy wrote.

Henry said the Maryland Department of Health and Mental Hygiene does not plan to take any action against the city. State police are continuing a criminal inquiry into the shooting.

Baltimore Police Commissioner Anthony W. Batts said Tuesday that he "knows what happened out there" and "has a good feel for the procedural breakdown." A part-time member of his security detail was among the veteran officers present. But Batts would not go into detail about the events surrounding the shooting, citing the ongoing investigations.

Tactical teams are always looking for large abandoned buildings to use for training, according to Chris Grollnek, a former police SWAT officer and training coordinator in Texas.

"When I was assigned to SWAT, we used to ask patrol officers that if you come across an abandoned building or something that's going to get demolished, if you see a [phone] number on the side of it, get the number," said Grollnek, who works for Texas-based Countermeasure Consulting Group on efforts to combat mass shootings.

He said police want foreign environments for training to keep tactical teams sharp and prepared for any scenario. Large buildings such as hospitals and office campuses offer the multiple rooms and floors needed to practice for school shootings and hostage situations.

"The buildings offer that surprise element and the element of the unknown," Grollnek said. "It's very hard to facilitate the element of surprise and provide a training area that hasn't been used over and over and over."

While training shootings are rare nationwide, others have occurred during similarly unauthorized exercises.

An officer had suggested they could use the building for training "if things weren't too busy," and they accessed the building through an unlocked door after having been called there a night earlier for a 911 hang-up call, the report said.

They unloaded their weapons and completed an hour of training, then reloaded their firearms after finishing the exercise. But an officer asked if they could continue, and at some point while the sergeant was demonstrating proper footwork he accidentally pulled the trigger and struck another officer.

The sergeant was cleared of criminal wrongdoing, including assault and reckless conduct, because he did not intentionally draw his gun or intentionally pull the trigger, according to the report.

W.T. Gaut, a retired Birmingham, Ala., police master training officer and an Alabama state police officer who now works as a court-certified expert in police practices, said it is cheaper for cash-strapped agencies to find abandoned buildings for training than to build training complexes.

He said it takes a lot of searching to find a perfect setting that's far enough from neighborhoods and other distractions, but once such a rare training site is found it's common for it to be shared by multiple agencies.

"That's not unusual," Gaut said. "When you have one county agency using it, everyone tends to use it."

The Baltimore Police Department said it will not release policies and procedures related to training exercises, even after being told by a federal judge last week that its policies are not protected from public disclosure.